I found a weird bug: every time i try to open the kreegan chest in the second floor of Colony Zod the game crashes.

i tried this in both software and hardware mode and in fullscreen or windowed mode, the game always crashes when i try to open it.

is there something important in it?

Given the trap value for chests there, you might miss out on artifacts or relics. If your party is already equipped with good items, then the bug is not worth the chance for decent treasure.

grayface's patch may or may not solve this problem. Try it out if it changes something.